Sheet feeding apparatus



Nov. 25, 1947. 1 I c, s, s 'fz 2,431,514

SHEET FEEDING APPARATUS Filed Sept. 15, 1944 4 Sheets-Sheet 1 I I m I 73mm 7 g CLIFFORD s. SELTZER Nov. 25, 194-7. c, s SELTZER 2,431,514

' SHEET FEEDING APPARATUS Filed Sept. 15, 1944 4 Sheets-Sheet 3 wonCLIFFORD S. SELTZER NW5 25%,, 1%4? g, g, SELTZER SHEET FEEDING APPARATUSFiled Sept. 15, 1944 4 Sheets-Sheet 4 R E 7.- T .L E s S D m F, W L CPatented Nov. 25, 1947 SHEET FEEDING APPARATUS Cliflord S. Seltzer,Warren, Ohio, assignor to The Taylor-Winfield Corporation, Warren, Ohio,a

corporation of Ohio Application September 15, 1944, Serial No. 554,326

This invention relates to the art of sheet feeding and more particularlyto improved apparatus for automatically supplying individual sheets froma stack or stacks of the sheets to the automatically operated machinessuch as forming presses, tubular body makers, and 4 furnish suchindividual stock sheets or blanks in' a' more reliable manner than hasheretofore been attained by devices employed afor comparable purposes.

Other objects of the invention are to provide automatic apparatus forthe purposes stated which is more rugged and reliable in operation; toprovide in such apparatus a greater flexibility of adjustments forjvarious sizes and thicknesses of the sheets tobe handled and to reducethe time required for changing over the apparatus to handle sheets ofdifferent size and thickness; to'materially reduce the tendency ofapparatus of the subject nature to feed more than one sheet or blank ata time and to reduce to a minimum the time required for the essentialmovements of the timed elements whereby the productive output of theapparatus is materially increased; and to provide sheet feedingapparatus which i operative to maintain an uninterrupted flow of sheetsto the receiving machine while the apparatus is being reloaded with bulkstacks of the sheets.

A more specific object of the invention is the provision of animprovedautomatic sheet feeding apparatus which is capable of receiving andhandling very heavy bulk stacks of the sheets while neverthelessmaintaining an uninterrupted and uniform flow of individual separatedsheets to the receiving device withwhich the sheet feeding apparatus isassociated. Thus, the employrnent of the principles of the presentinvention allows the construction and eflicient operation of whollyautomatic and high speed sheet feeding machines in connection with heavysheet stock or substantial size.

Another object of the invention is the provision of an. improved sheetseparating apparatus of the stack top take-off type. J

Still further objects of the invention include the provision of animproved vacuum cup actuating assembly for separating individual sheetse'nt invention;

. 2 of an improved general assembly in sheet feeding apparatus of thekind which is operative to maintain an uninterrupted flow of individualsheets whereby a portion only of the operative elements of the completeassembly need be rendered readily inoperative to allow thereplenishingand/or rearranging of the base or bulk stack of the sheets.

The above and other objects and advantages of the invention will becomeapparent upon consideration of the following detailed specification andthe accompanying drawing wherein there is disclosed a preferredembodiment of the invention.

In the drawing:

Figure 1 is a front elevation of a machine constructed according to theprinciples of the pres- Figure 2 is an end elevation, partly in section,of the apparatus of Figure 1;

Figure 3 is a plan view of the apparatus of Figure 1;

' Figure 4 is a vertical section along the lines IV-IV of. Figure 3;

Figure 5 is a fragmentary sectional view taken along the line V-V ofFigure 2;

Figure 6 is a fragmentary sectional view taken I I along the line VI-VIof Figure 1; and

Figure 7 is a longitudinal sectional view of one of the vacuum cupactuating devices utilized in the assembly of Figure 1.

In the drawing, reference numeral Ill designates a base which isU-shaped in plan and of the base I0 support a, housing I5 while asimilar but reversed housing I6 is supported on the columns II and I2which extend upwardly from the right leg of the base I 0. As will becomeapparent later, housings I5 and I6 support substantially all theoperative elementsof the complete assembly and to lend strength andrigidity to this supporting structure a strut I1 rigidly interconnectsthe housings I5 and I6 at the forward end of the machine. suitableinterconnections are made between the various columns and the base Illas well as between the various colu'nns and the housings I5 and It toinsure the maintenance ofthe vertical alignment and parallelism of thevarious columns.

Extending upwardly and forwardly of the rear portion of the base I 0 isa bulk stock rack ,con-

It should be understood that 'A similar housing 23 enclosing a.

sisting of a plurality of spaced brackets I8 held assembled by a bolt I9and suitable spacing sleeves I9 as will be understood. Mounted on therear center portion of the shelf provided by the brackets I8 is a block20 on which is mounted a housing 2I (see Figures 1 and 4) whichslideably encloses a finger 22 for movement toward and away from thecenter of the machine. similar slideable finger 24 is supported independing relation by the strut II. Fingers 22 and 24 are urged inwardlyby suitable spring means 22' and 24' and have wedge-like detents Ontheir inner ends to support an auxiliary sheet stack 25. Fingers 22 and24 are also each provided with a recess to receive a cam I22 each ofwhich isarranged to be rotated by a lever-lever 26 rotating the cam inhousing 2| and lever 21 rotating the cam in housing 23. For reasons tobe described below these cams are provided to retract the fingers 22 and24- thereby withdrawing the projecting portions of the detents thereoffrom the upward path of travel of the sheets to be added to the bottomof stack 25. Such sheet adding or replenishing means will be describedfollowing the description of the mechanism utilized to separate sheetsfrom the top of the principal stack supported on the rack provided bythe brackets I8.

Slideably mounted on the columns II and I2 is a housing 28 (Figures 2,and 6) which is provided with a horizontal inwardly directed guidingchannel 29 in which is slidea-blymounted a bar 36 having a wedge-shapedinner end tapering to a knife edge to enter between adjacent sheets ofastack to lift the sheet or sheets which lie above the knife edge. For apurpose to be hereinafter described sufficient clearance is allowedbetween the top of the bar 30 and the ceiling of the channel 29 to allowthe bar 36 vertical movement to an extent slightly greater than thethickness of the sheets being handled. The extent of this clearance maybe adjusted by longitudinally moving the wedge block 3i. Bar 30 andblock 3I are each provided with a longitudinally extending slot throughwhich extends a spline shaft 32 axially but rotatably secured to anddepending downwardly from the housing I5. Bar 30 is recessed to receivea rotatable screw 33 which is held against 4 endwise movement relativeto the bar and'which meshes with a gear 34' rotatably mounted in thehousing 28. Gear 34 is splined on a shaft 35 axially held by butrotatable with respect to and depending downwardly .from the housing,I5: Thus upon rotation of shaft 35 bar 30 is moved inwardly or outwardlywhile an adjustment of the location of the range of such movement of thebar may be effected by rotating screw 33, The latter adjustment is madein resetting the machine to handle stock of different size and it shouldbe understood that screw"33 is normally locked against rotation. Mountedin a thimble 36 depending downwardly from the principal body portion ofthe housing 28 is a collar 31 also splined on shaft 32. Collar 31carries a pair of diametrically opposed pivot pins for mounting togglelinks 38 and 39. Referring to Figure 6, clamping shoes 46 and 4| areslideablymounted in suitable openings provided in the housing 28 andthese shoes are engaged by and'are adapted to be moved outwardly by thetoggle links 38 and 39, respectively, into pressure engagement with thecolumns II and I2, respectively, whereby upon rotation of shaft 32 meansis provided to securely lock the housing 28 against vertical slidingmovement on the columns II and I2.

Extending across the-top of the machine and journaled in suitablesupports I5I and I52 extending upwardly from the housings I5 and I6 is ashaft .42 on which is keyed a cam 43 having operative relation with alever35' keyed to the top end of the spline shaft 35 whereby the latteris rotated in response to rotation of the shaft 42. Shaft 42 also mountsa second cam 44 which has operative relation with a. crank 32 ,keyed tothe top of spline shaft 32 whereby shaft 32 may also be rotated inresponse to rotation of shaft 42. Suitable driving mechanism, not shown,is provided to rotate shaft 42 back and forth through approximately a270 total range and, inpractice, means is provided to'vary theperiodicity of this oscillation as well as to interrupt this oscillationunder either manual or automatic control. The

a normal cycle of operation is such that when the blade 36 is inretracted position by operation of the spline shaft the shaft 32 is insuch position that the toggle links 36 and 39 are straightened wherebythe housing 28 is securely clamped to the columns II and I2. Shaft 35now operates to move blade 36 inwardly and upon the inner edge ofthe-blade engaging'the top of the stack below the top sheet which isthereby separated as illustrated in Figure 5, shaft 32 rotates to breakthe toggles thus releasing the clamps 46 and M and permitting thehousing 28 to drop a distance represented by the space between the topsurface of the blade 36 and the upper guide surface 29. Immediatelythereafter shaft 32 reverses to again clamp the housing 28 to thecolumns II and I2 after which shaft 35 operates to retract the blade 36.As the blade clears the stack it drops slightly by gravity in its guideinto position to enter below the next lower sheet in the stack. Itshould be observed that this mode of operation permits the separatingblade 36 to be lowered intermittently in accordance with the spacing ofthe adjacent sheets in the stack and in this manner normal tolerances inthe thickness of the stack cannot effect such accumulative error in thepositioning of the separating blade as would interfere with theconsecutive separation of a uniform number of sheets. This resultsfromthe fact that the respective thicknesses of the consecutive sheetsdetermines directly the extent of the downward increments of movement ofthe housings 28. As shownin Figure 1, an identical separatin assembly isprovided on the right side of the machine.

The means provided to lift the sheets separated by the blades 30 fromthe bulk stack supported on rack I8 and to raise such sheets to fourvertically reciprocable parts 45, 46, 41 and 46 one of which isslideably mounted on each of the four square columns I3 and I4. Thesquare nature of columns I3 and I4 holds the parts 45-48 againstrotation. Each of the parts 45, 46, 41 and 48 carries a spring pressedlifting latch 49 shown in Figures 3 and 4. Parts 45, 46, 41 and 48 areeach made of two pieces adjustable with respect to each other wherebyadjustment may be made for different size sheets as will be understood.Provision is made to raise and lower each of these parts in unison andin timed sequence with respect to the operation of the separatingmechanism previously described. Such raising and lowering means includesa pair of drums 56 and SI keyed on the lock'shaft 42.

. Secured to drum 56 and encircling the same in one direction is a chain52 (Fig. 3) which passes over an idler 53 journaled in housing I6 andover idler 51 is connected to-part 48 while a four chain 58 secured toand encircling drum in the opposite direction and entrained over idler59 is connected to part 45. All 'such connections between the chains andparts are accomplished by providing each of the parts with an aperturethrough which extends freely the assov ciated chain, the bottom end ofthe same having attached thereto a weight 58 (Figure 2) which may engagean undersurface of the part. {The function of the weights 50 is tomaintain the chains taut regardless of the positions of the parts 45-48.As shown in Figures 2 and 6 housing 28 has integral wings 5| and 62which partially encompass the columns B and l4 and which are arranged tobe engaged by lower surr top sheet feeding device is operativeregardless.

faces of the parts 45-48. It should be apparent that upon oscillation ofshaft 42 parts 45-48 will be raised in unison a sufllcient distance totransfer the successive sheets separated from the bulk stack by theblades 30 to the under side of the auxiliary stack 25. The extent ofdownward movement of the parts45-48 which carry the latches 49, however,is predetermined by the position of the housings 28. Thus latches 49descend only sufliciently to enable their operative tapered edges toengage below the sheet separated by the separating apparatus. Asapparent from Figures 1 and 3, levers 26 and 21 are engaged by uppersurfaces of the parts 45 and 48 as these parts approach their upperlimit of travel so that fingers 22 and 24 (Figure 4) are retracted, inproper timed sequence, to permit the sheet being elevated to be added tothe bottom of stack'25. At this time the auxiliary stack is, of course,supported on the latches '49 but upon the start of downward movement ofthese latches the cams I22 in housings 2i and 23 begin to move torelease the fingers 22 and 24 to allow the projecting edges thereof toagain engage the bottom surface of the auxiliary stack.

The individual sheets are fed successively to the feed line from the topof the auxiliary stack 25 and to separate the top sheets from theauxiliary stack proper I provide a pair of suction cup assemblies 64which are carried on a bar 65 spanning the housings l5 and I5. Referringto Figure '7, each of the assemblies .54 comprises a cylinder 66 whichis closed: at both ends and has a fiuid inlet 61 at its lower end and avent 68 open to the atmosphereat its upper end. Slideably mounted incylinder 66 is an inner cylinder 69 enclosing a piston III which isattached to a rod H carrying a suction cup 12 at its lower end. Anopening 13 through rod H and piston I8 provides communication betweenthe space within cup 12 and the. space within cylinder 59 above .piston10. An aperture 14 is provided in the upper portion of the side wall ofthe cylinder 59 and a cooperating aperture 15 is provided in the upperportion of the side wall of the cylinder 56. Ports 6'! are connectedwith a source of fluid pressure through a valve, not shown, operated inaccordance with the operation of the machine or equipment to which thesheets are to be fed. At the start of a cycle of operation cylinder 69is inlowermost position as indicated in dotted ,brings the leading edgeportion of. the sheet into contact with a driven magnetic roll 16 towhich the sheet is attracted and still further upward movement ofcylinder 69 brings apertures I4 and 15 into register which breaks thevacuum thus releasing the cup. Roll 16 is 'now' free to advance thespaced sheet-under guide 11 into a pair of pinch rolls 18. After thesheet clears the top of the stack 25 the above mentioned valve operatesto release all pressure from the ports 61 and the cup "then fall .downinto engagement with the next succeeding top sheet of the stack 25. Itshould be apparent that this of changes in the elevation of the to'p ofthe auxiliary stack 25. As will presently appeal this feature is highlyadvantageous.

To provide for the uninterrupted feeding of the sheets through the pinchroll 18 even during the time required to place a new stack of sheets onthe rack formed of the brackets I8 the mechanism employed to transferthe sheets from the top of the main bulk stack resting on the bracketsl8 to the bottom of the auxiliary stack 25 and driven by the shaft 42 asdescribed above is operated at a speed slightly in excess of the demandsof a machine or equipment to which the sheets .are supplied so thatnormally auxiliary stack 25 contains a predetermined minimumnumber ofsheets. Upon interruption of the transfer apparatus as is required inreplenishing the stock on the brackets 18 the number of sheets in thestack 25 diminishes but the supply thereon is slowly brought back tonormal upon the resumption of the operation of the transfer apparatus byreason of this greater speed of operation. To limit the height ofauxiliary stack 25 I provide .a limit switch 19 which, through suitableconreplenished. To effect thi mode of operation a depending link 80 ispivotally mounted on each of the two housings 28 and these links arearranged to be rotated inwardly by knobs 8i readily accessible from thefront of the machine. When so rotated inwardly they are in the paths oftravel of shoulders 82 projecting from the parts 45, 45,

' 41 and 48 so that upon the next upwardstroke lines and if now fluidpressure is admitted through inlet 6! cylinder 58 is moved upwardly thusexpanding the space in cylinder 89 above of these parts as results fromthe pulling action 'of the chains 52, 54, 56 and 58 the completeseparating mechanism including the two housings 28 and all appendagesthereof will be moved to upper position. Amanual switch 83 ,is providedto interrupt operation of shaft 42 and by opening this switch at thetime the parts and housings reach the upper end of .their stroke suchparts and housings will be held in upper position by the chains 52, 54,56 and 58 coupled with the now immobile shaft 42 thereby leaving therack l8 clear for the replenishment of the stock thereon.

Upon the switch then being turned on the transfer mechanism resumes itsoperation to replenish the now diminished stock in the stack 25. The

' operation of the machine illustrated in the draw- 7 8 45-48 thesefingers wardly sufllcient to position below the side edge -parts duringthe excess plurality of sheets in auxiliary'stack which is normallysupported on fingers 22 and 24 and that there is 'a'pile of sheets inthe main stack resting on bracket shaft 42 results in the followingsequence of operations. 'When shaft 42 is at the limit of its clockwisetravel, as viewed in Figure 2, the auxiliary stack 25 is supportedduring the prior upward movement of the parts 49 raised'the previouslyseparated top sheet of the lower or main stack into engagement with thebottom sheet of the upper or auxiliary stack and beyond thus lifting theauxiliary stackfree'of the fingers 22 and24. Such upward movement issufilcient to enable the sheet being added to the bottom of theauxiliary stack to pass up above and beyond the fingers 22v and At thistime the latter are in retracted position by reason of the actuation ofthe lever arms 28 and 21 by the upward movement of parts 45 and 48. a

As the shaft 42 beginsto rotate in a counterclockwise direction, asviewed in Figure 2, the parts 45-48are lever arms 28 and 21 are allowedto tilt down- .relieve cams I22 thereby 18, the periodic'oscillation ofon the fingers ,49 since lowered in unison and, first, the

1 bracket So that housings 28 to which links 88 are attached will beraised-free and clear of bracket I8.- Switch "83 is used to stopirotation or oscillation of shaft -42' when all the parts are Thisclears and holds clear the space for insertion of a new rack or stack ofsheets on the l8. It should be observed that the slotted nature of theassembled bracket I8 is such that the fork of aconventional shop lifttruck may be employed to load the rack of sheets on the bracket.

. Upon re-actuation of switch Bland release of links 88 normal operationof the machine is automatically-resumed.

It should be particularly observed that during stock replenishment inthe-manner outlined above there needbe no interruption whatever in thefeeding of sheetsfrom the top of the auxiliary stack by means of theperiodically actuated vacuum lifters 84, magnetic roll I8, and pinchrolls 18. As heretofore explained the frequency of actuation of thevalve, not shown. controlling allowing fingers 22 and 24 to move intosupporting portions of the descending. auxiliary stack 25. Uponcontinued downward movement of parts 45-48 the fingers 49 loweraway-from the bottom of the auxiliary stack which then rests on fingers22 and 24. Downward movement of parts 45-48 is arrested by the stops 8|,62 on housings 28 but before such downward movement is stopped thespring actuated fingers 49 will have snapped over the outer edges of thewhich top sheet has already been separatedby the blades 38. Shaft 42always progresses through its full cycle of course, regardless of theextent of vertical travel of the parts 45-48, the

chains 52, 54, 56, 58 simply sliding through these travel and beingmaintained taut by the weights 88. Thus, after shaft 42 reverses andafter the chain slack is taken up p the weights 88 engage parts45-48 toraise the same in unison to lift and add another sheet to the bottom ofthe auxiliary stack in the manner described immediately above.

During the time that the parts 45-48 are elevated and are lowering thefingers 49 the cams 43 and 44 operate through spline shafts 32 and 35 tofirst actuate clamps 48 and 4|, then to withdraw or retract the bladesSit-allowing them to drop slightly by gravity into position for entrybelow the top sheet of the main or lower stack-then to reinsert or movethe blades 38 inwardly to separate the top sheet from this stack, andthereafter to release the clamps 48, 4| to allow the housings 28 to dropby gravity an interval determined by the vertical clearance in guides29, as explained above. Cams '43 and 44 are so designed that this cycleis fully completed before the parts 45-48 are brought to rest on stops61, 82 regardless of variations in the height of the main or lowerstack. a

As explained above. the auxiliary stack 25 is normally replenished frombelow at a rate greater .than the rate of feed from the top of theauxiliary stack so that normally a full component of sheets appears inthe auxiliary stack, the limit switch 19 operating to maintain thecomponent n'umber substantially constant. If now the main stack isdepleted the links 88 may be swung inwardly for engagement by shoulders82 on parts 41 and 48 top sheet of the main stack the flow of. air tounits 84 is somewhat less than the frequency of oscillation of shaft 42so that upon resumption of feed from the main stack the partiallydepleted auxiliary stack will be slowly replenished to its fullcomplement of sheets.

The above specifically described embodiment of the invention should beconsidered'as illustrative only as obviously many changes may be madetherein without departing from the spirit or scope of the invention.Reference should therefore be had to the appended claims in determiningthe scope'of the invention.

What I claim is:

1. Sheet feeding apparatus comprising in combination a bulk stockrack,'a support for an auxiliary upper stack of sheets above said rack,means above said support to separate individual I sheets from the top ofsaid auxiliary stack and to thereafter movethe same may from saidauxiliary stack, a sheet separating device-arranged to follow thelocation of the. top of a lower stack ,.of sheets mounted on saidrack'and operative to separate the top sheets thereof in succession. avertically reciprocable transfer apparatus operative to lift theseparated sheets from the top -of the lower stack to the bottom of theupper stack, and means on said device to limit the downward movement ofsaid transfer apparatus.

2. Apparatus according to claim 1 further including means effectingdownward movement of said device in each cycle of operation a distanceequal only to the thickness of the sheet separated by said device duringsaid cycle regardless of variations in the thickness of successivesheets in said lower stack 3. A sheet separating device of the stack toptake-off type comprising in combination a vertically extending member, asupport slideably mounted for vertical movement on saidmember, means toclamp said support to said member, a separating tool, said supportcarrying a horizontally disposed guide for slideably receiving saidtool, said tool having a knife edge for entering below the bottomsurface of the top sheet of the stack, means to operate said clamp andto move said tool outwardly and inwardly of said stack in sequence,means to lower said tool when outwardly ofsaid stack, and means tomomentarily release said clamping means while said tool is in inwardposition.

4. A sheet separating device of the stack top take-off type comprisingin combination a support, a stack rack, a support mounted for verticalmovement relative to said rack, an elongated in uppermost position.

separating tool, a horizontally disposed channel in said support forslideably receiving said tool,

said channel having upper and lower surfaces spaced a distance equal tothe vertical dimension of said tool plus approximately the thickness ofthe sheets to be separated, means to slide said tool in said guideinwardly and outwardly of the stack, and means to prevent loweringmovement of said support when said tool is clear of the stack butpermitting free lowering movement of said support when said tool isengaged with the stack.

5. A device according to claim 4 further including adjustable means tovary the spacing of said upper and lower surfaces whereby the extent ofvertical movement of said tool relative to said support in each cycle ofoperation may be varied.

6. A sheet separating device of the stack top take-off type comprisingin combination a support mounted for vertical movement downwardly alongsaid stack, a movable sheet separating blade carried by said support,means to move said blade inwardly and outwardly of the stack, and meansto lower said support a distance equal substantially only to thethickness of the sheet or sheets to be separated during each such cycleof movement of said blade.

7. Sheet feeding apparatus comprising in combination a bulk stack rackto receive a lower stack of sheets, a sheet separating device of thestack top take-01f type to separate successively the top sheets of saidstack from said stack, retractable means supporting an upper auxiliarystack of sheets, vertically reciprocable means for transferring theseparated sheets from the top of the lower stack to the bottom of theupper stack, means operable synchronously with said transferring meansfor retracting said retractable means whereby the sheet or sheets beingtransferred may be added to the bottom of said auxiliary stack, andmeans to supply individual sheets in succession from the top of saidauxiliary stack.

8. Sheet feeding apparatus comprising in combination a, bulk stack rackto receive a lower stack 10 of sheets, a, sheet separating device of thestack top take-off type to separate successively the top sheets of saidstack from said stack, means to support, an upper auxiliary stack ofsheets, means to feed individual sheets off the top of said auxiliarystack, means to transfer the sheets separated from the lower stack tothe'bottom of said auxiliary stack, and means to move said device toupper position and to maintain said device and said means to transfer inupper position whereby the supply of sheets on said rack.may

REFERENCES CITED The following references are of record in the file ofthis patent:

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